date:20151012

[Pw_forum] slab Ewald sum quantum espresso

2015-10-12 Thread Niels R. Walet

The title says it all--Has anyone ever tried to replace the 3D Ewald sum 
in quantum espresso with a quasi-2D slab Ewald sum (yes, I know, that 
would not be general, and requires on using certain type of crystal unit 
cells).
If it has bot been done, am I daft to think it should not be a total 
mistake to implement it?
Niels

-- 
Prof. Niels R. Walet   Phone:  +44(0)1613063693
School of Physics and AstronomyFax:+44(0)1613064303
The University of Manchester   Mobile: +44(0)7905438934
Manchester, M13 9PL,  UK   room 7.7, Schuster Building
email: niels.wa...@manchester.ac.uk
web:   http://www.theory.physics.manchester.ac.uk/~mccsnrw

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[Pw_forum] starting magnetization in DFT+U calculation

2015-10-12 Thread Krishnaiah Kallamadi

what value can i give as starting magnetization for Fe2O3 in DFT+U
calculations. can i give any random value?





Thanks and Regards,
K.Krishna
JRF, CSIR-SERC
India
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Re: [Pw_forum] slab Ewald sum quantum espresso

2015-10-12 Thread Oliviero Andreussi

Dear Niels,

I am probably not the most suited to answer and, probably, the best 
mailing list to address this problem is the qe-developers one 
(q-e-develop...@qe-forge.org). Moreover, it is not fully clear to me 
what you are planning to do (Ewald sum is only part of the electrostatic 
energy of the system, the other relevant one being the Hartree term, are 
you proposing a 2D version of that as well? or you include all 
electrostatic under the Ewald label? or you refer to something else...), 
so I apologize in advance if I got it wrong.

On my side, I have been working with reduced dimensionality systems and 
I have been (recently) implementing the 2D and 1D version of the 
Martyna-Tuckermann correction schemes (Mináry, P., Tuckerman, M. E., 
Pihakari, K. A., & Martyna, G. J. (2002) The Journal of Chemical 
Physics, 116(13), 5351–5362. http://doi.org/10.1063/1.1453397). I 
haven't committed anything yet, as I am still debugging the code, but I 
plan to make it public as soon as everything is sound.

On the other hand, I have also implemented some quadratic correction 
schemes (for 0D and 2D systems, some details in Andreussi, O., & 
Marzari, N. (2014). Electrostatics of solvated systems in periodic 
boundary conditions. Physical Review B, 90(24), 245101. 
http://doi.org/10.1103/PhysRevB.90.245101) inside the Environ module 
that we are developing, www.quantum-environment.org.

I guess any new fully working (and maintained) feature would be a plus 
for the code, even if there are already similar things under development.

Best,

Oliviero Andreussi

Senior Postdoctoral Associate

École Polytechnique Fédérale de Lausanne (EPFL) and

Università della Svizzera Italiana (USI) of Lugano

Switzerland

On 10/12/2015 02:32 PM, Niels R. Walet wrote:
> The title says it all--Has anyone ever tried to replace the 3D Ewald sum
> in quantum espresso with a quasi-2D slab Ewald sum (yes, I know, that
> would not be general, and requires on using certain type of crystal unit
> cells).
> If it has bot been done, am I daft to think it should not be a total
> mistake to implement it?
> Niels
>

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Re: [Pw_forum] starting magnetization in DFT+U calculation

2015-10-12 Thread Krishnaiah Kallamadi

How can i find the starting magnetization value for Fe2O3 in DFT+U
calculations?

On Mon, Oct 12, 2015 at 6:51 PM, Giuseppe Mattioli <
giuseppe.matti...@ism.cnr.it> wrote:

> [image: Boxbe]  Giuseppe Mattioli (
> giuseppe.matti...@ism.cnr.it) is not on your Guest List
> 
> | Approve sender
> 
> | Approve domain
> 
>
>
> Dear K. Krishna
>
>+
>Variable:   starting_magnetization(i), i=1,ntyp
>
>Type:   REAL
>Description:starting spin polarization on atomic type 'i' in a spin
>polarized calculation. Values range between -1 (all
> spins
>down for the valence electrons of atom type 'i') to 1
>(all spins up). Breaks the symmetry and provides a
> starting
>point for self-consistency. The default value is zero,
> BUT a
>value MUST be specified for AT LEAST one atomic type in
> spin
>polarized calculations, unless you constrain the
> magnetization
>(see "tot_magnetization" and
> "constrained_magnetization").
>Note that if you start from zero initial magnetization,
> you
>will invariably end up in a nonmagnetic (zero
> magnetization)
>state. If you want to start from an antiferromagnetic
> state,
>you may need to define two different atomic species
>corresponding to sublattices of the same atomic type.
>starting_magnetization is ignored if you are performing
> a
>non-scf calculation, if you are restarting from a
> previous
>run, or restarting from an interrupted run.
>If you fix the magnetization with "tot_magnetization",
>you should not specify starting_magnetization.
>In the spin-orbit case starting with zero
>starting_magnetization on all atoms imposes time
> reversal
>symmetry. The magnetization is never calculated and
>kept zero (the internal variable domag is .FALSE.).
>+
>
> HTH
> Giuseppe
>
> On Monday, October 12, 2015 06:32:06 PM you wrote:
> > what value can i give as starting magnetization for Fe2O3 in DFT+U
> > calculations. can i give any random value?
> >
> >
> >
> >
> >
> > Thanks and Regards,
> > K.Krishna
> > JRF, CSIR-SERC
> > India
>
> 
> - Article premier - Les hommes naissent et demeurent
> libres et ègaux en droits. Les distinctions sociales
> ne peuvent être fondèes que sur l'utilitè commune
> - Article 2 - Le but de toute association politique
> est la conservation des droits naturels et
> imprescriptibles de l'homme. Ces droits sont la libertè,
> la propriètè, la sùretè et la rèsistance à l'oppression.
> 
>
>Giuseppe Mattioli
>CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
>v. Salaria Km 29,300 - C.P. 10
>I 00015 - Monterotondo Stazione (RM), Italy
>Tel + 39 06 90672836 - Fax +39 06 90672316
>E-mail: 
>http://www.ism.cnr.it/english/staff/mattiolig
>ResearcherID: F-6308-2012
>
>
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Re: [Pw_forum] starting magnetization in DFT+U calculation

2015-10-12 Thread Giuseppe Mattioli

Dear K. Krishna

   +
   Variable:   starting_magnetization(i), i=1,ntyp

   Type:   REAL
   Description:starting spin polarization on atomic type 'i' in a spin
   polarized calculation. Values range between -1 (all spins
   down for the valence electrons of atom type 'i') to 1
   (all spins up). Breaks the symmetry and provides a starting
   point for self-consistency. The default value is zero, BUT a
   value MUST be specified for AT LEAST one atomic type in spin
   polarized calculations, unless you constrain the 
magnetization
   (see "tot_magnetization" and "constrained_magnetization").
   Note that if you start from zero initial magnetization, you
   will invariably end up in a nonmagnetic (zero magnetization)
   state. If you want to start from an antiferromagnetic state,
   you may need to define two different atomic species
   corresponding to sublattices of the same atomic type.
   starting_magnetization is ignored if you are performing a
   non-scf calculation, if you are restarting from a previous
   run, or restarting from an interrupted run.
   If you fix the magnetization with "tot_magnetization",
   you should not specify starting_magnetization.
   In the spin-orbit case starting with zero
   starting_magnetization on all atoms imposes time reversal
   symmetry. The magnetization is never calculated and
   kept zero (the internal variable domag is .FALSE.).
   +

HTH
Giuseppe

On Monday, October 12, 2015 06:32:06 PM you wrote:
> what value can i give as starting magnetization for Fe2O3 in DFT+U
> calculations. can i give any random value?
> 
> 
> 
> 
> 
> Thanks and Regards,
> K.Krishna
> JRF, CSIR-SERC
> India

- Article premier - Les hommes naissent et demeurent
libres et ègaux en droits. Les distinctions sociales
ne peuvent être fondèes que sur l'utilitè commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et 
imprescriptibles de l'homme. Ces droits sont la libertè,
la propriètè, la sùretè et la rèsistance à l'oppression.

   Giuseppe Mattioli
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
   v. Salaria Km 29,300 - C.P. 10
   I 00015 - Monterotondo Stazione (RM), Italy
   Tel + 39 06 90672836 - Fax +39 06 90672316
   E-mail: 
   http://www.ism.cnr.it/english/staff/mattiolig
   ResearcherID: F-6308-2012

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[Pw_forum] ESM implementation

2015-10-12 Thread Niels Walet

I was looking at the ESM implementation in QE, and note that case iv of Otani 
and Sugino doesn't seem to be implemented (\epsilon_r finite in the bulk on 
both sides)--what is the reason for that?
Does that have anything to do with the expressions for the Hartree energy, 
which I can't find in the original paper?
Niels

---
Prof. Niels R. Walet Phone:  +44(0)1613063693
School of Physics and Astronomy Fax:+44(0)1613064303
The University of Manchester   Mobile: +44(0)7516622121
Manchester, M13 9PL,  UK  room 7.7, Schuster Building
email: niels.wa...@manchester.ac.uk
web:   
http://www.theory.physics.manchester.ac.uk/~mccsnrw<../../owa/redir.aspx?C=8f9098c1943846dcba17536b8618a38a&URL=http%3a%2f%2fwww.theory.physics.manchester.ac.uk%2f%7emccsnrw>
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Re: [Pw_forum] help for calculating Hubbard parameter

2015-10-12 Thread Matteo Cococcioni

Dear Forzad,

if you search the QE webpage (in the "resources" section, I believe) you
will find the notes and lectures from several past QE schools, workshops,
tutorials and there should be some about the calculation of U. One is in
the Santa Barbara school from 2009. A second one should be among the notes
from a school in Pune last year.

hope this will help you.

best regards,

Matteo



On Thu, Oct 8, 2015 at 12:11 PM, Farzad Molani  wrote:

> Dear QE users,
> I want to calculate Hubbard parameter. Has any body  a tutorial "step by
> step" for calculating the hubbard parameter? Is this input file correct?
> How can I use the output file?
>
>
> &CONTROL
>   calculation  ="scf",
>   pseudo_dir   = "./",
>   restart_mode = 'restart',
>   outdir   = "./",
>   prefix   = "geraphene-Fe-ldaU",
>   verbosity= 'high',
>   tprnfor   = .true.,
>   tstress   = .true.,
> /
> &SYSTEM
>   ibrav   = 4,
>   celldm(1)   = 9.282,
>   celldm(3)   = 2.035,
>   nat = 9,
>   ntyp= 2,
>   ecutwfc = 44.2,
>   ecutrho =300,
>   nspin   = 2,
>   starting_magnetization(1)=0.5,
>   starting_magnetization(2)=0.5,
>   occupations='smearing',
>   smearing   ='m-v',
>   degauss=0.003,
>   lda_plus_u = .true.
>   Hubbard_alpha(2)=-0.04,
> /
> &ELECTRONS
>   conv_thr  = 1.0d-10,
>   mixing_beta = 0.5d0,
>   diagonalization  = 'cg',
> /
> &IONS
> /
> &CELL
> /
> ATOMIC_SPECIES
> C   12.010   C.pz-rrkjus.UPF
> Fe  55.8452  Fe.pz-nd-rrkjus.UPF
> ATOMIC_POSITIONS {angstrom}
> C   -0.034035640   1.396956433   4.962804121
> C1.208811211   0.679456444   4.961853267
> C2.451565749   1.396929605   4.962300355
> C3.664662075   0.696596615   5.017209108
> C   -1.247079599   3.532441567   5.017139042
> C   -0.034018302   2.832082543   4.961775758
> C1.208707850   3.549535163   4.962481191
> C2.451470952   2.831954512   4.963586323
> Fe   1.207584375   2.113742807   6.427714456
> K_POINTS automatic
>  5 5 1 0 0 0
>
>
> Best regards
> Farzad Molani,
> Ph.D in Computational Chemistry
> Department of Chemistry,
> Islamic Azad University of Sanadaj
> Tel.: 009891 4442 3308
>
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Re: [Pw_forum] Esm bc2 SCF Convergence issue

2015-10-12 Thread Minoru Otani

Dear Paresh,

Basically, the ESM method is completely independent with spin polarization and
LDA+U, you can probably use those switches with the ESM. 

Since the convergence problem with the ESM is frequently coming from the atomic 
position. Could you attach the whole input file? 

Best regards,
Minoru

-
 Minoru Otani
 Nanomaterials Research Institute (NRI),
 National Institute of Advanced Industrial
 Science and Technology (AIST)
 e-mail：minoru.ot...@aist.go.jp
 Phone : +81-29-861-5202
-

On Oct 9, 2015, at 9:27 PM, paresh rout  wrote:

> Dear all,
> I am facing scf convergence problem while doing a calculation on a slab 
> interface by using esm_bc=bc2 .The scf does not converge after 100 iteration 
> .I have given 14 angstrom vacuum in my slab. Here I am providing my input 
> file details. Kindly correct me if something needs to be changed . I have 
> also played with mixing beta and degauss value but nothing improved. Any help 
> would be highly appreciated.
> 
> &control
> calculation = 'scf'
> restart_mode='from_scratch',
> wf_collect=.true.
> prefix='AFM'
> !   tstress = .true.&control
> calculation = 'scf'
> restart_mode='from_scratch',
> wf_collect=.true.
> prefix='CRO-CMO-AFM'
> !   tstress = .true.
> !   tprnfor = .true.
> etot_conv_thr = 1.0E-8
> forc_conv_thr = 1.0E-5
> !   nstep=400
> !   dt=5.D0
> max_seconds =86000
> outdir = '/scratch/vardha/my_scratch/tmp_CRO-CMO_AFM_84/'
> pseudo_dir = '/home1/vardha/PSEUDO/'
> !tefield=.true.,
> !dipfield=.true.,
> 
>  /
>  &system
> ibrav=0,
> celldm(1)=10.43601926
> !   celldm(2)=1.0,
> !celldm(3)=5.4902631
> nat=84,
> ntyp=6,
> ecutwfc =65.0,
> ecutrho =640,
> nspin = 2
> !nosym=.true.
> !edir=3
> !eamp=0.00
> !emaxpos=0.82
> !eopreg =0.045
>  assume_isolated='esm'
>  esm_bc='bc2'
>  esm_w=9.45 !If assume_isolated = 'esm', 
> determines the position offset
>  esm_nfit=4
> !esm_efield=0.d0
> starting_magnetization(1) = 0.0
> starting_magnetization(2) = 0.0
> starting_magnetization(3) = 0.5
> starting_magnetization(4) =-0.5
> occupations="smearing"
> smearing="mv"
> degauss=0.03
> lda_plus_u = .true.
> lda_plus_u_kind=0
> Hubbard_U(1)= 1.d-10
> !   Hubbard_J(1,1)=1.0
> Hubbard_U(2)= 1.d-10
> Hubbard_U(3)= 1.d-10
> Hubbard_U(4)= 1.d-10
> !   Hubbard_J(1,2)=1.0,
> 
>  /
>  &electrons
> mixing_mode = 'local-TF'
> !   diago_full_acc=.true.
> electron_maxstep=110
> mixing_beta = 0.3
> !   startingpot='file'
> conv_thr =  1.0d-9
> diagonalization="david"
>  /
> !&IONS
> !ion_dynamics='bfgs',
> /
> !&CELL
> ! cell_dynamics='bfgs',
> ! press=0.00,
> /
> CELL_PARAMETERS (alat)
>  1.00   0.00   0.00
>  0.00   1.00   0.00
>  0.00   0.00   8.025345273
> 
> !   tprnfor = .true.
> etot_conv_thr = 1.0E-8
> forc_conv_thr = 1.0E-5
> !   nstep=400
> !   dt=5.D0
> max_seconds =86000
> outdir = '/scratch//my_scratch/tmp_AFM_84/'
> pseudo_dir = '/home1/PSEUDO/'
> !tefield=.true.,
> !dipfield=.true.,
> 
>  /
>  &system
> ibrav=0,
> celldm(1)=10.43601926
> !   celldm(2)=1.0,
> !celldm(3)=5.4902631
> nat=84,
> ntyp=6,
> ecutwfc =65.0,
> ecutrho =640,
> nspin = 2
> !nosym=.true.
>  assume_isolated='esm'
>  esm_bc='bc2'
>  esm_w=9.45  ! (5 angstrom)
>  esm_nfit=4
> !esm_efield=0.d0
> starting_magnetization(1) = 0.0
> starting_magnetization(2) = 0.0
> starting_magnetization(3) = 0.5
> starting_magnetization(4) =-0.5
> occupations="smearing"
> smearing="mv"
> degauss=0.03
> lda_plus_u = .true.
> lda_plus_u_kind=0
> Hubbard_U(1)= 1.d-10
> !   Hubbard_J(1,1)=1.0
> Hubbard_U(2)= 1.d-10
> Hubbard_U(3)= 1.d-10
> Hubbard_U(4)= 1.d-10
> !   Hubbard_J(1,2)=1.0,
> 
>  /
>  &electrons
> mixing_mode = 'local-TF'
> !   diago_full_acc=.true.
> electron_maxstep=110
> mixing_beta = 0.3
> !   startingpot='file'
> conv_thr =  1.0d-9
> diagonalization="david"
>  /
> !&IONS
> !ion_dynamics='bfgs',
> /
> !&CELL
> ! cell_dynamics='bfgs',
> ! press=0.00,
> /
> CELL_PARAMETERS (alat)
>  1.00   0.00   0.00
>  0.00   1.00   0.00
>  0.00   0.00   8.025345273
> 
> Kind Regards
> Paresh Chandra Rout
> Research Scholar
> INDIAN INSTITUTE OF SCIENCE EDUCATION AND RESEARCH, BHOPAL
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Re: [Pw_forum] slab Ewald sum quantum espresso

2015-10-12 Thread Minoru Otani

Dear Niels,

In the ESM method, we probably use the 2D Ewald sum.

If you want to see what I did, probably, the subroutine ‘esm_ewaldg_bc1’ 
(open boundary condition along the z-direction) in the esm.f90 is appropriate 
for you.

Best regards,
Minoru

-
 Minoru Otani
 Nanomaterials Research Institute (NRI),
 National Institute of Advanced Industrial
 Science and Technology (AIST)
 e-mail：minoru.ot...@aist.go.jp
 Phone : +81-29-861-5202
-

On Oct 12, 2015, at 5:32 AM, Niels R. Walet  
wrote:

> The title says it all--Has anyone ever tried to replace the 3D Ewald sum 
> in quantum espresso with a quasi-2D slab Ewald sum (yes, I know, that 
> would not be general, and requires on using certain type of crystal unit 
> cells).
> If it has bot been done, am I daft to think it should not be a total 
> mistake to implement it?
> Niels
> 
> -- 
> Prof. Niels R. Walet   Phone:  +44(0)1613063693
> School of Physics and AstronomyFax:+44(0)1613064303
> The University of Manchester   Mobile: +44(0)7905438934
> Manchester, M13 9PL,  UK   room 7.7, Schuster Building
> email: niels.wa...@manchester.ac.uk
> web:   http://www.theory.physics.manchester.ac.uk/~mccsnrw
> 
> ___
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Re: [Pw_forum] ESM implementation

2015-10-12 Thread Minoru Otani

Dear Niels,

Yes, I did not implement the boundary condition (iv) into QE. As contrary to 
other
boundary conditions (ii) and (iii), we need to introduce additional classical 
charge
distribution (such as the modified Poisson Boltzmann, eq. (A3) in the paper). To
solve this additional equation, we need to add another self-consistent procedure
inside the KS solver. It may harm for the total calculation time. This was the 
reason
why I did not implement the boundary condition (iv).

Regarding the Hartree energy, if we use the boundary condition (iv), we need to
modify the Hartree, Ewald, and Local potential energy part accordingly. 

Best regards,
Minoru

-
 Minoru Otani
 Nanomaterials Research Institute (NRI),
 National Institute of Advanced Industrial
 Science and Technology (AIST)
 e-mail：minoru.ot...@aist.go.jp
 Phone : +81-29-861-5202
-

On Oct 12, 2015, at 8:35 AM, Niels Walet  wrote:

> I was looking at the ESM implementation in QE, and note that case iv of Otani 
> and Sugino doesn't seem to be implemented (\epsilon_r finite in the bulk on 
> both sides)--what is the reason for that?
> Does that have anything to do with the expressions for the Hartree energy, 
> which I can't find in the original paper?
> Niels
> 
> ---
> Prof. Niels R. Walet Phone:  +44(0)1613063693
> School of Physics and Astronomy Fax:+44(0)1613064303
> The University of Manchester   Mobile: +44(0)7516622121
> Manchester, M13 9PL,  UK  room 7.7, Schuster Building
> email: niels.wa...@manchester.ac.uk
> web:   http://www.theory.physics.manchester.ac.uk/~mccsnrw
> ___
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[Pw_forum] slab Ewald sum quantum espresso

[Pw_forum] starting magnetization in DFT+U calculation

Re: [Pw_forum] slab Ewald sum quantum espresso

Re: [Pw_forum] starting magnetization in DFT+U calculation

Re: [Pw_forum] starting magnetization in DFT+U calculation

[Pw_forum] ESM implementation

Re: [Pw_forum] help for calculating Hubbard parameter

Re: [Pw_forum] Esm bc2 SCF Convergence issue

Re: [Pw_forum] slab Ewald sum quantum espresso

Re: [Pw_forum] ESM implementation

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